What is the Difference Between Degenerate and Non-degenerate Semiconductor

The key difference between degenerate and non-degenerate semiconductors is that in degenerate semiconductors, the injection of electrons or holes is only possible from the Fermi energy level, whereas non-degenerate semiconductors can cause the formation of two types of contacts to organic material.

Semiconductors are materials having an electrical conductivity value that falls between the conductivity of conductors and insulators. Degenerate semiconductors are a type of semiconductors in which a high level of doping can be observed, making the semiconductor act as metal than a semiconductor.

1. Overview and Key Difference
2. What are Degenerate Semiconductors
3. What are Non-degenerate Semiconductors
4. Degenerate vs Non-degenerate Semiconductors in Tabular Form
5. Summary – Degenerate vs Non-degenerate Semiconductors

What are Degenerate Semiconductors?

Degenerate semiconductors are a type of semiconductors in which a high level of doping can be observed, making the semiconductor act as metal than a semiconductor. Unlike other types, this type of semiconductor does not obey the law of mass action (the law of mass action relates intrinsic carrier concentration with temperature and bandgap).

Degenerate vs Non-degenerate Semiconductor in Tabular Form

Figure 01: Semiconductor Doping

When considering a moderate doping level, dopant atoms create individual doping levels that are considered localized states with the ability to donate electrons or holes by thermal promotion to either conduction or valence bands. When the impurity level is high enough, the individual atoms that contribute to the impurity can become close enough, which causes doping levels to merge into another impurity band. Here, the behavior of such a system ceases to show the typical traits of a semiconductor. For example, an increase in the conductivity of the system can occur with the rise of temperature.

However, a degenerate semiconductor has fewer carriers compared to true metal. Therefore, the behavior is intermediate between a semiconductor and a metal.

What are Non-Degenerate Semiconductors?

Non-degenerate semiconductors are a type of semiconductors containing moderate levels of doping, and the dopant atoms are well separated from each other with negligible interactions. Moreover, dopant atoms exhibit separate energy levels, and these are usually formed below the conduction band edge or on top of the valence band edge.

In coordination compounds, upon the attachment of ligands, the transition element ion is no longer isolated. Therefore, the dative bonding from the ligands results in the splitting of the five d orbitals into two sets. The energy of these two sets is not equal. Therefore, we can describe them as being non-degenerate orbitals.

What is the Difference Between Degenerate and Non-degenerate Semiconductor?

Semiconductors are materials having a conductivity that lies between a conductor and a non-conductor. The key difference between degenerate and non-degenerate semiconductors is that in degenerate semiconductors, the injection of electrons or holes is only possible from the Fermi energy level, whereas non-degenerate semiconductors can cause the formation of two types of contacts to organic material.

The below infographic presents the differences between degenerate and non-degenerate semiconductors in tabular form for side-by-side comparison.

Summary – Degenerate vs Non-degenerate Semiconductor

Degenerate semiconductors are a type of semiconductors in which a high level of doping can be observed, making their functions similar to that of metals. Non-degenerate semiconductors are a type of semiconductors containing moderate levels of doping where the dopant atoms are well separated from each other with negligible interactions. The key difference between degenerate and non-degenerate semiconductors is that in degenerate semiconductors, the injection of electrons or holes is only possible from the Fermi energy level, whereas non-degenerate semiconductors can cause the formation of two types of contacts to organic material.

Reference:

1. “Degenerate Semiconductor.” Wikipedia, Wikimedia Foundation, 24 Jan. 2022.
2. Connor, Nick. “What Is Degenerate Semiconductor – Definition.” Radiation Dosimetry, 14 Dec. 2019.